On Thursday, March 12, 2015 at 12:20:57 PM UTC-4, Fred McKenzie wrote:
In article ,
Tom W3TDH wrote:

The other radio will be a UHF D-STAR hotspot.

Tom-

What kind of range are you trying to achieve with the hotspot? The
little antenna that came with a UHF DVAP covers my property fairly well,
just sitting on a table.

I connected it to a Larsen dual-band mag-mounted antenna stuck on top of
a filing cabinet, and get about a half mile range when mobile. The DVAP
puts out about a tenth of a Watt. I suspect it can hear the 50 Watt
mobile a lot further away.

If you want range, consider taking the DVAP with you and connecting to
the internet through a cellular modem or telephone. I'm considering
getting a D-HAP, which holds everything but the radio and the cellular
connection. http://www.portableuniversalpower.com/dhap/

73,
Fred
K4DII

Fred

I must confess that I am a little up in the air on the D-STAR hot spot issues. The hot spot is part of a club project that I would be hosting at my home. The club is using Motorola M120 radios at the low end of their power output which is around Twenty Five Watts I believe. The effort is intended to cover as much of our service area as is practical with Seventy Centimeter D-STAR coverage. The strange thing is that I am not a D-STAR user. I use the clubs centrally located analog repeater for my UHF coverage needs. I'm only hosting the local node in order to support the club effort.

Tom Horne W3TDH

Tom,
You have too many of the same band antenna's concentrated in one place.
No matter how hard you try, they aren't going to play nice with each other.
I read 14 posts and no one gave an even close right answer to your question.
The answer is that you need to construct a tower, no less than 100', near your house in order to even try to do what you wish to do.
Even then, you will need feet of separation vertically in order to get the antenna's to play nice with each other.
Your SWR is going to be all messed up, because you have too many of the same antenna's in the same proximity.

The only good 6 / 2 / 70 cm antenna that I could recommend would be the Diamond v2000. This is the only antenna that I am aware of that has a decent amount of gain - if you want to call it that, along with being semi resonant on all three bands.

What you are doing is back-feeding everything that you transmit back into the receive of the front ends of all of the radios in your shack when any one radio transmits. Unless it is in your budget to replace all those radios on a semi annual schedule, you will eventually experience that each of those transceivers will eventually become deaf.

I have seen filters promoted in QST that allows two operators on two different bands to share a beam antenna with two transceivers, as long as each transceiver stays on it's band it is ok.

But there is a hell of a difference between 20 meters - 14 MHz - CW and 40 meters Phone.

Even though 70 cm is not a harmonic of 2m, and even though there is a heck of a disparity between 440 MHz and 146 MHZ there is always going to be problems when dealing with FM, and Digital modes.

I have to take your wife's side on this one!

Tell your club to go out and buy an acre of ground and put up a transmitter and a tower and put their packet and their D-Star crap on their tower, and then you can tune to their tower frequency if you so choose. You are killing not only all of your transceivers by what you are trying to do, but you are diminishing the range at which you yourself can operate...

If you can hear other repeaters / more than 20 miles away though all of that RF noise you have created, you will be lucky..

It doesn't matter if the radios are all turned on or off, as long as they are connected to the coax / antenna, they are still going to experience front end overload.

On Wednesday, March 11, 2015 at 7:11:14 PM UTC-4, Brian Reay wrote:
Tom W3TDH wrote:
I am looking for recommendations for a dual band antenna that will serve
two separate radios. The reason that I want to use a single antenna is
that I have a limited number of mounting points for antennas. At present
it will be hard for SWMBO; as in Rumpole's spouse, She Who Must Be
Obeyed; to tolerate the use of both our home's gable ends and the chimney
being used to support antennas. I am planning to replace my Diamond X-30
with a triband vertical for Six, Two, and .7 Meters. The chimney will
then support a rotor aimed Two and .7 Meter beam. The second gable end
will support the Two meter / Seventy Centimeter dual band vertical that I
am asking for help in selecting.

One radio will be a two meter packet node which will be used as a Winlink
Radio Message Server. The other radio will be a UHF D-STAR hotspot. I
am willing to pay what is needed to to get the best antenna for this
application but I don't want to waste money ineffectively. So the two
meter radio will be in the 144 MHz portion of the band and I don't yet
actually know were the D-STAR hotspot will be run. I have a DCI filter
and diplexer to keep the two radios from actually knowing of each others
existence. Since a hotspot is not supposed to be a terribly wide area
installation I would imagine that I do not want an extremely high gain
antenna but I am perfectly open to be reeducated on that. The difficulty
is that I would guess that the Radio Message Server / Packet would
benefit from as much horizontal gain as can be achieved. I have a home
brewed collinear two meter J-Pole that has been a good performer on two
meters and presents a low SWR on 440 MHz. I have yet to master antenna
modeling but I would imagine; given all the warnings I have read on line;
that it has poor radiation pattern on UHF. Is it likely to be too poor a
performer for a hot spot on UHF?

I really am asking because I want to know. I am not looking for
encouragement to do something that will be ineffective. Thank you in
advance for any help you may be willing to offer.

--
Tom Horne W3TDH

Diamond do a number of other antennas similar to the x30, essentially
longer, with more gain. I would suggest you look at their website and pick
one to match you budget, acceptable profile, etc.

It may be worth investing in another tribander, you may just want the third
band in the future and it will save another negotiation with Senior
Management. Or you could take my approach and have an XYL who is licensed
;-)

73
Brian
G8OSN/W8OSN

Brian

Thank you for the second tribander idea. I do not now have a 220 MHz base antenna. So using a tribander instead of a dual band antenna will add that additional bands worth of capability to me base station. Since I am very heavily involved in local EMCOMM preparation that is a very worthwhile thing to do. It must be a good day because I learned something new.

--
Tom Horne W3TDH

In article ,
Tom W3TDH wrote:

Thank you for the second tribander idea. I do not now have a 220 MHz
base antenna. So using a tribander instead of a dual band antenna will
add that additional bands worth of capability to me base station. Since
I am very heavily involved in local EMCOMM preparation that is a very
worthwhile thing to do. It must be a good day because I learned
something new.

My home base-station antenna is a Comet CX-333 (2m/220/440), with a
triplexer in the shack (Kenwood TS-2000 for 2m and 440, and a Kenwood
I-forget-what for 220). It seems to work very much as one would
expect. No complaints at all.

On Wednesday, March 11, 2015 at 7:11:14 PM UTC-4, Brian Reay wrote:
Tom W3TDH wrote:
I am looking for recommendations for a dual band antenna that will serve
two separate radios. The reason that I want to use a single antenna is
that I have a limited number of mounting points for antennas. At present
it will be hard for SWMBO; as in Rumpole's spouse, She Who Must Be
Obeyed; to tolerate the use of both our home's gable ends and the chimney
being used to support antennas. I am planning to replace my Diamond X-30
with a triband vertical for Six, Two, and .7 Meters. The chimney will
then support a rotor aimed Two and .7 Meter beam. The second gable end
will support the Two meter / Seventy Centimeter dual band vertical that I
am asking for help in selecting.

One radio will be a two meter packet node which will be used as a Winlink
Radio Message Server. The other radio will be a UHF D-STAR hotspot. I
am willing to pay what is needed to to get the best antenna for this
application but I don't want to waste money ineffectively. So the two
meter radio will be in the 144 MHz portion of the band and I don't yet
actually know were the D-STAR hotspot will be run. I have a DCI filter
and diplexer to keep the two radios from actually knowing of each others
existence. Since a hotspot is not supposed to be a terribly wide area
installation I would imagine that I do not want an extremely high gain
antenna but I am perfectly open to be reeducated on that. The difficulty
is that I would guess that the Radio Message Server / Packet would
benefit from as much horizontal gain as can be achieved. I have a home
brewed collinear two meter J-Pole that has been a good performer on two
meters and presents a low SWR on 440 MHz. I have yet to master antenna
modeling but I would imagine; given all the warnings I have read on line;
that it has poor radiation pattern on UHF. Is it likely to be too poor a
performer for a hot spot on UHF?

I really am asking because I want to know. I am not looking for
encouragement to do something that will be ineffective. Thank you in
advance for any help you may be willing to offer.

--
Tom Horne W3TDH

Diamond do a number of other antennas similar to the x30, essentially
longer, with more gain. I would suggest you look at their website and pick
one to match you budget, acceptable profile, etc.

It may be worth investing in another tribander, you may just want the third
band in the future and it will save another negotiation with Senior
Management. Or you could take my approach and have an XYL who is licensed
;-)

73
Brian
G8OSN/W8OSN

Brian

Should I follow your suggestion I would need to also provide protection for the radio connected to the third band segment. Do you know of any reason why connecting two separate filters to the same feed line would not work.

Can I anticipate any ill affect from placing a coaxial Tee fitting across the output of one filter and connecting a jumper to the output of another filter in order to connect the transceivers to the multiband antenna? Would there be any additional concerns be raised if one of the two filters was the dual band model with separate connections for each of it's two bands on the end being used for input connections? What about if I make up the assembly using Three separate filters with Two of them connected to TEE fittings..

--
Tom Horne W3TDH

On 15/03/15 15:42, Tom W3TDH wrote:
On Wednesday, March 11, 2015 at 7:11:14 PM UTC-4, Brian Reay wrote:
Tom W3TDH wrote:
I am looking for recommendations for a dual band antenna that will serve
two separate radios. The reason that I want to use a single antenna is
that I have a limited number of mounting points for antennas. At present
it will be hard for SWMBO; as in Rumpole's spouse, She Who Must Be
Obeyed; to tolerate the use of both our home's gable ends and the chimney
being used to support antennas. I am planning to replace my Diamond X-30
with a triband vertical for Six, Two, and .7 Meters. The chimney will
then support a rotor aimed Two and .7 Meter beam. The second gable end
will support the Two meter / Seventy Centimeter dual band vertical that I
am asking for help in selecting.

One radio will be a two meter packet node which will be used as a Winlink
Radio Message Server. The other radio will be a UHF D-STAR hotspot. I
am willing to pay what is needed to to get the best antenna for this
application but I don't want to waste money ineffectively. So the two
meter radio will be in the 144 MHz portion of the band and I don't yet
actually know were the D-STAR hotspot will be run. I have a DCI filter
and diplexer to keep the two radios from actually knowing of each others
existence. Since a hotspot is not supposed to be a terribly wide area
installation I would imagine that I do not want an extremely high gain
antenna but I am perfectly open to be reeducated on that. The difficulty
is that I would guess that the Radio Message Server / Packet would
benefit from as much horizontal gain as can be achieved. I have a home
brewed collinear two meter J-Pole that has been a good performer on two
meters and presents a low SWR on 440 MHz. I have yet to master antenna
modeling but I would imagine; given all the warnings I have read on line;
that it has poor radiation pattern on UHF. Is it likely to be too poor a
performer for a hot spot on UHF?

I really am asking because I want to know. I am not looking for
encouragement to do something that will be ineffective. Thank you in
advance for any help you may be willing to offer.

--
Tom Horne W3TDH

Diamond do a number of other antennas similar to the x30, essentially
longer, with more gain. I would suggest you look at their website and pick
one to match you budget, acceptable profile, etc.

It may be worth investing in another tribander, you may just want the third
band in the future and it will save another negotiation with Senior
Management. Or you could take my approach and have an XYL who is licensed
;-)

73
Brian
G8OSN/W8OSN

Brian

Should I follow your suggestion I would need to also provide protection for the radio connected to the third band segment. Do you know of any reason why connecting two separate filters to the same feed line would not work.

Can I anticipate any ill affect from placing a coaxial Tee fitting across the output of one filter and connecting a jumper to the output of another filter in order to connect the transceivers to the multiband antenna? Would there be any additional concerns be raised if one of the two filters was the dual band model with separate connections for each of it's two bands on the end being used for input connections? What about if I make up the assembly using Three separate filters with Two of them connected to TEE fittings.




It depends.

For example:

Some, duplexers are just an LPF and a HPF. Say your 2m filter is LPF and
your 70cm filter is HPF and your 3rd band is 220MHz (the one you wish to
Tee in).

If the Cut Off frequency of the HPF is such that is will allow too much
of the 220 MHz to pass to the 70cm radio, you could have an issue with
enough 220MHz reaching the 70cm radio to be an issue. Likewise of for
the 2m radio but with the LPF cut off.

You really need to know the performance of the filters you are using.

I don't know the unit you mentioned, I would suggest you study the data
sheet and see what its performance is at the frequency you plan to 'Tee'
in.

Ideally, build (or buy) a unit designed to work with three signals,
which you may be able to do using the unit you have when you know the
characteristics.

On Sunday, March 15, 2015 at 12:36:28 PM UTC-4, Brian Reay wrote:

It depends.

For example:

Some, duplexers are just an LPF and a HPF. Say your 2m filter is LPF and
your 70cm filter is HPF and your 3rd band is 220MHz (the one you wish to
Tee in).

If the Cut Off frequency of the HPF is such that is will allow too much
of the 220 MHz to pass to the 70cm radio, you could have an issue with
enough 220MHz reaching the 70cm radio to be an issue. Likewise of for
the 2m radio but with the LPF cut off.

You really need to know the performance of the filters you are using.

I don't know the unit you mentioned, I would suggest you study the data
sheet and see what its performance is at the frequency you plan to 'Tee'
in.

Ideally, build (or buy) a unit designed to work with three signals,
which you may be able to do using the unit you have when you know the
characteristics.

Brian

I was specifically referring to the Digital Communications Incorporated band pass filters that I had identified earlier in the thread. I have in hand a DCI-146-444-DX-DB I was thinking of adding a DCI-223.5-3H for 125 Centimeter band for the 146/220/446 tri-band antenna. That would give me three separate input ports to attach the three separate transceivers to.

On the 6,2,& 0.7 Meter multi-band antenna I would buy a DCI-146-444-DB and a DCI-6M-53 MHz-2-4p. That way I could connect a dual band 146/446 Mhz radio to the dual band filter and the Six Meter Transceiver to the Six Meter band pass filter inlet.

The spec sheets for all of these filters can be seen at the manufacturers web site at
http://www.dci.ca/?Section=Products&SubSection=Amateur.

--
Tom Horne W3TDH

On 3/16/2015 3:55 PM, Tom W3TDH wrote:
On Sunday, March 15, 2015 at 12:36:28 PM UTC-4, Brian Reay wrote:

It depends.

For example:

Some, duplexers are just an LPF and a HPF. Say your 2m filter is LPF and
your 70cm filter is HPF and your 3rd band is 220MHz (the one you wish to
Tee in).

If the Cut Off frequency of the HPF is such that is will allow too much
of the 220 MHz to pass to the 70cm radio, you could have an issue with
enough 220MHz reaching the 70cm radio to be an issue. Likewise of for
the 2m radio but with the LPF cut off.

You really need to know the performance of the filters you are using.

I don't know the unit you mentioned, I would suggest you study the data
sheet and see what its performance is at the frequency you plan to 'Tee'
in.

Ideally, build (or buy) a unit designed to work with three signals,
which you may be able to do using the unit you have when you know the
characteristics.

Brian

I was specifically referring to the Digital Communications Incorporated band pass filters that I had identified earlier in the thread. I have in hand a DCI-146-444-DX-DB I was thinking of adding a DCI-223.5-3H for 125 Centimeter band for the 146/220/446 tri-band antenna. That would give me three separate input ports to attach the three separate transceivers to.

On the 6,2,& 0.7 Meter multi-band antenna I would buy a DCI-146-444-DB and a DCI-6M-53 MHz-2-4p. That way I could connect a dual band 146/446 Mhz radio to the dual band filter and the Six Meter Transceiver to the Six Meter band pass filter inlet.

The spec sheets for all of these filters can be seen at the manufacturers web site at
http://www.dci.ca/?Section=Products&SubSection=Amateur.


Tom,

It should work nicely. DCI's filters are good quality, and you should
easily be able to work all three bands with this setup.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On Monday, March 16, 2015 at 3:40:35 AM UTC-4, Jeff wrote:
Should I follow your suggestion I would need to also provide protection for the radio connected to the third band segment.

Do you know of any reason why connecting two separate filters to the same feed line would not work.

Can I anticipate any ill affect from placing a coaxial Tee fitting across the output of one filter and connecting a jumper to the output of another filter in order to connect the transceivers to the multiband antenna?

Would there be any additional concerns be raised if one of the two filters was the dual band model with separate connections for each of it's two bands on the end being used for input connections?

What about if I make up the assembly using Three separate filters with Two of them connected to TEE fittings.


Hi

Using a tee piece is not a good idea as it would effectively be putting
a stub on your line, and depending on the length of the coax connections
and the frequencies that you are operating on and the out of band
impedances of the filters, it may or may not cause you problems.

As things have got a bit disjointed as the thread as progressed would it
be possible for you to give a short and accurate description of what you
are actually relying to achieve, and then perhaps a solution could be
suggested.

Jeff

Jeff

It is all here in the rest of the thread but here goes. I have only three antenna mounting points available on my home for antennas to serve:
a dedicated two meter transceiver for a digital node,
a dedicated Seventy Centimeter transceiver for a D-STAR hot spot.
a separate 120 CM transceiver
the six meter band of multiband transceiver
a dual band 146/446 transceiver

That is five radios that need to be able to use Six Separate VHF/UHF frequencies with as many as four transceivers operating at the same time. Two of those transceivers would be operating as automatic stations so as many as three of those transmitters may be transmitting at the same time. Two of the three may even be on the same band given that their will be an automatic station on both Two Meters and Seventy Centimeters and I may be operating as a manual control operator on either of those bands at any given time.

I initially asked for advise on which dual band antenna to use to serve a 144 Mhz and a 440 MHz digital stations.

Someone then suggested that I use two tri-band antennas in order to provide all band capability for FM operations on 6, 2, 1.25, and 0.7 Meter bands while still operating the two automatic stations on 144 & 440. I would use vertical separation to reduce the de-sensing on the common band stations.

I then asked for advise on any foreseeable problems with using the DCI filters to effectively separate the signals at the radios and yet allow the transceivers to share two multi-band antennas to cover the needed bands with only two mounting points.

I'm saving the third mounting point for stacked Yagi-Uda beams to provide additional range on 146/440 for the repeaters at the extreme ends of the service area of the Forecast Office that I am serving as Assistant Coordinator for Net Management in their Skywarn Program. I am hoping that between the beams and two amplifiers with receive pre amps I will be able to take reports when appropriate from some of the more distant sub nets. I have done this previously with temporary masts from this location so I am very hopeful that it will work using more permanently mounted beams. All of that is so you will know why the third mounting point is not available for the needed omnidirectional vertical antennas.

I hope that makes the expanding questions clear.

--
Tom Horne W3TDH

On 17/03/15 08:12, Jeff wrote:
It is all here in the rest of the thread but here goes. I have only
three antenna mounting points available on my home for antennas to serve:
a dedicated two meter transceiver for a digital node,
a dedicated Seventy Centimeter transceiver for a D-STAR hot spot.
a separate 120 CM transceiver
the six meter band of multiband transceiver
a dual band 146/446 transceiver

That is five radios that need to be able to use Six Separate VHF/UHF
frequencies with as many as four transceivers

operating at the same time. Two of those transceivers would be
operating as automatic stations so as many as three of

those transmitters may be transmitting at the same time. Two of the
three may even be on the same band given that their

will be an automatic station on both Two Meters and Seventy Centimeters
and I may be operating as a manual control operator

on either of those bands at any given time.

I initially asked for advise on which dual band antenna to use to
serve a 144 Mhz and a 440 MHz digital stations.

Someone then suggested that I use two tri-band antennas in order to
provide all band capability for FM operations on 6, 2, 1.25,

and 0.7 Meter bands while still operating the two automatic stations on
144 & 440. I would use vertical separation to reduce the

de-sensing on the common band stations.

I then asked for advise on any foreseeable problems with using the DCI
filters to effectively separate the signals at the radios

and yet allow the transceivers to share two multi-band antennas to cover
the needed bands with only two mounting points.

I'm saving the third mounting point for stacked Yagi-Uda beams to
provide additional range on 146/440 for the repeaters at the

extreme ends of the service area of the Forecast Office that I am
serving as Assistant Coordinator for Net Management

in their Skywarn Program. I am hoping that between the beams and two
amplifiers with receive pre amps I will be able to take reports when
appropriate from some of the more distant sub nets. I have done this
previously with temporary masts from this location so I am very hopeful
that it will work using more permanently mounted beams. All of that is
so you will know why the third mounting point is not available for the
needed omnidirectional vertical antennas.

I hope that makes the expanding questions clear.

Tom

The first thing that you have to consider is that none of the DFCI
filters will give you any protection when 2 radios are operating in the
same band, and paralleling things up with tee pieces is generally not a
good idea.


The issue with using Tee pieces is inadvertently inserting 'stubs' etc.
If care is taken to avoid this, eg by keeping leads very very short,
then at the frequencies being used, things should be OK. After all, a
duplexer is just a set of filters in one box (ie the connections are
very very very short). In fact, as the DCI filters are bandpass (based
on Tom's post, I've not looked at the specs), they are probably better
in some ways than some duplexers which just use LPFs and HPFs.
(Triplexers tend to use at least one BPF but some only use an
additional HPF.)